The remote effects of radiation after hypofractionated irradiation with protons of Ehrlich ascites carcinoma in mice

This work focuses on the study of remote effects (duration of remission, recurrence rate, and average lifespan) in mice with Ehrlich ascites carcinoma exposed to oligofractionated irradiation with a pencil scanning beam of protons depending on the volume of the tissue being irradiated and the interval between dose fractions. The results show higher antitumor efficacy and a considerable increase in the average life span of mice after hypofractionated irradiation with a pencil scanning beam of protons at a total dose of 60 Gy of the gross tumor volume compared with the planning target volume.     

Inhibition of the repair of neutron-induced DNA single-strand breaks in experimental tumor cells

Nicotinamide and arabinoside cytosine mixed with hydroxyurea were shown to influence the relative amount of double-stranded DNA in Ehrlich ascites tumor cells in vitro subjected to single irradiation (10-30-52 Gy) and in Guerin's carcinoma in rat lungs exposed to fractionated 6 MeV neutron-radiation (1.25 Gy X 4). The DMF values for Ehrlich ascites tumor were a function of a dose range and the duration of the drugs' effect. Guerin's carcinoma DNA was found to be affected more readily when treated with radiation and drugs than when exposed to neutron radiation alone.     

The effect of ascitic fluid on the growth of Ehrlich tumor and Lewis carcinoma]

In the study of the effect of ascitic fluid and dialysate of Ehrlich ascites tumor cells (m.m. less than 15 kDa) on the growth of Ehrlich and Lewis carcinoma it was found that the ascitic fluid significantly decreased the size of Ehrlich tumor (by more than 50% on day 9-25 after the tumor cell inoculation). It also reduced Lewis carcinoma tumor volume by more than 30% during 3 weeks after the tumor cells inoculation. Dialysate of Ehrlich tumor cells significantly inhibited the growth of Ehrlich tumor too. It is suggested that this test-system simulates inhibition of a small tumor by a big tumor in vivo.     

The modelling of the growth of Ehrlich carcinoma and teratoma T-36 with ascitic fluid and tumor-cell dialysate]

The study of the effect of ascitic fluid and dialysate of Ehrlich ascites tumor cells (M.m. less than 15 kDa) on the growth of Ehrlich carcinoma and teratoma T-36 has shown that both the ascitic fluid and dialysate can protect tumor cells in vivo. The number of animals with tumors increased from 0% in control animals to 60 and 20%, respectively, in experimental ones after transplantation i.m. of 20 x 10(3) Ehrlich tumor cells into mice. Compared to control, ascitic fluid and dialysate of Ehrlich ascites tumor cells increased the rate of tumor growth to 195 and 153%, respectively. It is suggested that this test-system simulates the effect of tumor humoral factors in vivo.     

Immunomodulating effect of electromagnetic waves on production of tumor necrosis factor in mice with various rates of neoplasm growth

The effects of low-density centimeter waves (8.15-18 GHz, 1 microW/cm2, 1 h daily for 14 days; MW) on tumor necrosis factor production in macrophages of mice with different growth rate of a cancer solid model produced after hypodermic injection of Ehrlich carcinoma ascites cells into hind legs were studied. After irradiation, an increase in the concentration of tumor necrosis factor in immunocompetent cells of healthy and, specially, of tumor-bearing animals was observed; and the effect of stimulation was higher upon exposure of mice carrying rapidly growing tumors. We suggest that the significant immunomodulating effect of low-density microwaves can be utilized for tumor growth suppression.     

The effect of nonspecific immune stimulation with Corynebacterium parvum and polidin on the Ehrlich ascites tumor growth

Investigations were performed: a) to compare the effect of two nonspecific immunostimulants, Polidin and Corynebacterium parvum, on the development of Ehrlich ascites carcinoma in mice; b) to determine whether the effects are dependent on the tumor cell dose inoculated into the animals. C. parvum and Polidin administered prior to Ehrlich ascites tumor inoculation have a protective effect evidenced by a delay in tumor development, a retardation in tumor growth and a prolonged survival of the tumor host. The effect of immunostimulants was highly dependent on the tumor cell dose inoculated into mice and was more marked with C. parvum.     

Effect of electromagnetic microwave radiation on the growth of Ehrlich ascites carcinoma

Daily exposure of mouse recipients of Ehrlich ascites carcinoma to electromagnetic radiation of the microwave range leads to a change in the dynamics of tumor growth by decreasing the total number of cells. The number of tumor cells with blebbing morphological signs after microwave radiation increases gradually with tumor growth. The maximum content of tumor cells in the state of blebbing is observed during active proliferation in tumor-recipient mice of the control group (without irradiation).     

Tumor-Specific Transplantation Resistance in Mice after Treatment of Initial Tumors with Streptococcus thermophilus

Antitumor activity observed by treatment with Streptococcus thermophilus was further investigated. The mice cured from fibrosarcoma by treatment with heat-killed preparation of S. thermophilus, when challenged with fibrosarcoma failed to take up the tumor. However, these cured mice when challenged with sarcoma-180 or Ehrlich ascites carcinoma, did not show significant changes in tumor take and/or survival compared to their respective controls. Similarly, mice cured from sarcoma-180 were challenged with fibrosarcoma, sarcoma-180 or Ehrlich ascites carcinoma. Though there was no change in the mean survival time (MST) of the dying mice regarding sarcoma-180 or Ehrlich ascites carcinoma, there was 50 and 30% increase in the number of mice that showed total regression respectively over controls. However, there was no difference in the growth rate of fibrosarcoma. Similar observations were made with mice cured from Ehrlich ascites carcinoma, challenged with these tumors. These findings thus suggest that the antitumor response was tumor-specific and that tumor-associated antigens may have a role in imparting this specificity. Bacterial treatment non-specifically augmented this primary response.     

The effect of polycations on cell membrane stability and transport processes

Summary The interaction of poly-l-lysines of different molecular weights (PL) with Ehrlich ascites tumor cells was studied experimentally with respect to cell surface binding, cell electrophoresis, cytotoxicity and membrane permeability. Although they decrease the net negative charge of Ehrlich ascites cells similarly at low PL concentrations, low molecular weight PL was less cytotoxic and less damaging to the potassium transport mechanism than was high molecular weight PL. At certain PL concentrations, membrane damage was reversible on reincubation in PL-free media. The amount of bound polylysine as determined with fluorescent labeled polylysine was compared by electrophoresis to the amount of polylysine expressed on the electrokinetic surface. The results indicated that only a small fraction of polylysine bound to Ehrlich ascites tumor cells was electrokinetically detectable. The adsorption of polylysine to Ehrlich ascites tumor cells was not describable by the usual adsorption isotherms. It is suggested that the same number of monomeric lysine units of high and low molecular weight PL are adsorbed at the cell electrokinetic surface, but cytotoxicity is dependent on molecular weight. Although the negative charge of human red blood cells could be reversed at low PL concentrations, no such effect could be observed for ELD (a subline of Ehrlich ascites carcinoma) cells even at high PL concentrations. The relationship of PL binding to the stimulation of macromolecular uptake is discussed.     

中药麝香胶囊抑瘤作用的实验研究

目的探讨中药麝香胶囊对小鼠实验性肿瘤的疗效。方法昆明小鼠分别接种艾氏腹水癌、S-180、肝癌细胞株（hepatocellular carcinoma,HCC）三种癌细胞株,接种24h后开始给予中药麝香胶囊,每日1次,共10d。分高、中、低三个剂量给药（4、2、1g／kg以主药麝香药量计）。阳性对照以天仙丸胶囊（1g／kg）一次性灌服。阴性对照组以同体积生理盐水灌服。接种实体瘤动物于第10天处死,称瘤重,计算抑瘤率;接种腹水瘤动物,观察存活时间,计算生命延长率。结果中药麝香胶囊对实体癌有一定的抑瘤作用,但未达到药典规定的抑瘤率30％的要求;对腹水癌也有一定的抑瘤作用,但也未达到药典规定生命延长率50％的要求;统计学分析（P〉0．05）差异没有显著性。结论中药麝香胶囊抑瘤作用不明显,其配方及剂型有待进一步研究与改进。     

Punarnavine,an alkaloid from Boerhaavia diffusa exhibits anti-angiogenic activity via downregulation of VEGF in vitro and in vivo

Punarnavine, a quinolizidine alkaloid isolated from Boerhaavia diffusa is known to possess analgesic, anti-inflammatory, hepato-protective, immunomodulatory and anti-proliferative properties. However, its roles in tumor angiogenesis and the involved molecular mechanism are still unknown. Therefore, we examined its anti-angiogenic effects and mechanisms in vitro and in vivo. We examined the effect of punarnavine on VEGF-A expression by RT-PCR, Western blotting and ELISA. In vivo antiangiogenic activity was determined using sponge implant angiogenesis assay and antitumor activity was evaluated against Ehrlich ascites carcinoma tumor. Punarnavine significantly inhibited endothelial cell migration and invasion and capillary structure formation of HUVECs. Punarnavine significantly at 50 μM inhibited MMP-2 and MMP-9 expression in HUVECs in vitro. Punarnavine inhibited neovascularization in sponge implant assay. Punarnavine (15 mg/kg bw/d) treatment showed dose-dependent decrease in the ascitic fluid volume by 60.94% and tumor volume by 86.40% in Ehrlich ascites model. Reduction in peritoneal angiogenesis with punarnavine treatment suggests the anti-angiogenic activity of punarnavine. The present study sheds light on the potent anti-angiogenic of the punarnavine and can be extended further to develop therapeutic protocols for treatment of cancer.     

The role of endogenous glutathione in the actualization of the radiomodifying effect during the post-radiation period

It was shown on Ehrlich ascites tumor cells that for realization of the radioprotective effect of anoxia and beta-mercaptoethylamine normal content of glutathione is necessary not only at the time of irradiation but in the postirradiation period as well while glutathione content should be normal only after irradiation for realization of the radiotherapeutic effect of serotonin.     

Antitumor effect of lysine-isopeptides

Isopeptides (ε-peptides) of lysine, with a given Mw and low polydispersity (10–400 units), were synthesized to study the relationship between their chemical structure and biological effect. The designed compounds were of high purity, low polydispersity and high stereochemical purity. The effect of the compounds was tested on a human erythroleukemia cell line (K-562) and on four transplantable mouse tumors (L1210 lymphoid leukemia, P38 macrophage derived tumor, Ehrlich ascites carcinoma, Lewis lung tumor /LLT/). In case of the L1210 and P388 tumors and the Ehrlich carcinoma, survival of the animals was used as an indicator of the effect. In case of the Lewis lung tumor, the number and size of metastases in the lung and/or liver of treated and untreated mice were used as indicators. The polymers of polymerisation degree 80–120 (Mw 10.2–15.4 KD) showed the strongest antiproliferative effect both on K562 cells and the tumors growing in vivo. This effect was manifest with a significantly higher survival rate as compared to the control (L1210, P38, Ehrlich ascites), furthermore, by a decrease in the number and size of liver and lung metastases (LLT).     

Effect of lipid hydroperoxides on the yield of chromosome aberrations in irradiated cells

The combined effect of linoleic acid hydroperoxide and gamma-radiation on Ehrlich ascites tumor cells was not additive with regard to the formation of chromosome aberrations. When cells were preincubated in the presence of a subliminal hydroperoxide dose of 2.10(-5) M the number of aberrant cells increased after irradiation.     

The antitumor effect of bleomycin combined with bestatin against Ehrlich ascites carcinoma in mice

The effect of bleomycin against Ehrlich ascites carcinoma transplanted subcutaneously to mice used in combination with bestatin was investigated. Male Balb/c mice weighting approximately 20 g and bred in our laboratories were used in this study. Each mouse was injected in its left lateral abdominal region subcutaneously with 7 X 10(6) tumor cells in 0.2 ml of ascites fluid. The mice were divided into four groups: control, bestatin alone (5 mg/kg intraperitoneally on Days 9-14), bleomycin alone (10 mg/kg intraperitoneally on Days 7 and 8), and bestatin plus bleomycin. Our results show that bestatin enhances the antitumor effect of bleomycin against Ehrlich ascites carcinoma as measured by the increased survival rates. Being an agent of very low toxicity, bestatin should be considered as a part of the chemoimmunotherapy protocol.     

Bioflavonoid regulation of ATPase and hexokinase activity in Ehrlich ascites cell mitochondria.

(1) The mitochondrial ATPase (EC 3.6.1.3) Ehrlich ascites cell mitochondria, was inhibited by D-glucose under physiological concentrations of ATP. The generation of ADP by the mitochondrial bound hexokinase, seems to be the reason for the D-glucose inhibitory effect. Reversal of the inhibitory effect of ADP on Ehrlich ascites cell mitochondria ATPase by an ATP-regenerating system was achieved. (2) Dissociation of mitochondrial bound hexokinase from the mitochondria eliminated the inhibitory effect of D-glucose. Rebinding of the hexokinase to the mitochondria regenerated the D-glucose inhibitory effect on Ehrlich ascites cell mitochondria ATPase. (3) Bioflavonoids such as quercetin inhibit the mitochondrial hexokinase activity, but do not change the mitochondrial ATPase activity of isolated Ehrlich ascites tumor cell mitochondria. (4) The inhibitory effect of bioflavonoids on mitochondrial bound hexokinase activity is shown to be dissociable from the ascites tumor cell mitochondria and seems to be associated with regulatory rather than catalitic sites of the enzyme.     

Effect of nonspecific immune stimulation with BCG and polidin on the Ehrlich ascites tumor growth

Investigations were performed to study: 1) the antitumor effect of BCG pretreatment on the development of Ehrlich ascites tumor in mice; 2) the effect of BCG administration in relation to the period of time before tumor inoculation and the dose levels used, and 3) the antitumor effect of an associated pretreatment of BCG and Polidin on the development of Ehrlich ascites tumor. BCG administered prior to Ehrlich ascites tumor inoculation have a protective effect evidenced by a delay in tumor development, a prolonged survival of the tumor host and, in some cases, even inhibition of tumor growth. The effect of BCG was highly dependent on 1) the dose and the time of administration of BCG and) 2 the combined pretreatment of BCG and Polidin.     

The effect of cancer chemotherapy on lysosomal enzymic activities (acid phosphatase) of Ehrlich ascites carcinoma cells.

The distribution of acid phosphatase in Ehrlich ascites carcinoma cells was studied by histochemical techniques in mice treated with antitumoral agents (Tio-Tepa, Cosmegen). The results proved the accuracy of the histoenzymatic demonstration of APh activity for the study of early changes induced in Ehrlich ascites tumor by antitumoral drugs : these changes precede those revealed by routine histological methods and are related to the degree of sensitivity of the tumor to the drugs.     

Comparative effects of Yoshi-864 and busulfan on certain transplantable murine tumors.

Yoshi-864 extends markedly the survival times of mice bearing L1210 leukemia or Ehrlich ascites carcinoma. Busulfan, with methanesulfonate leaving groups identical with those of Yoshi-864, is without effect. Tumor cells from mice bearing the Ehrlich tumor and treated with Yoshi-864 have a persistent reduction in ability to synthesize DNA. Synthesis of DNA in cells from mice treated with busulfan is moderately suppresed at 48 hr after treatment, but returns virtually to the control value at 72 hr.     

Regulation of protein kinases activity by quercetin in Ehrlich ascites tumor cells

Cyclic AMP-independent protein kinase activities from Ehrlich ascites tumor cells, partially purified by DEAE-cellulose and phosphocellulose chromatography were inhibited by quercetin. The cyclic AMP in the tumor ascites cells and the cyclic AMP-dependent protein kinase activity from this tumor and from bovine and mouse tissues were unaffected by this drug. Since we reported that quercetin elevates cyclic AMP level in Ehrlich ascites tumor cells, this bioflavonoid may have a dual effect on the protein kinae activities in these cells, thus, increasing the cyclic AMP-dependent and decreasing the cyclic AMP-independent protein kinase activities.